Kim Jong Un unveils a new 8,700-ton nuclear-powered submarine, escalating tensions in the Pacific. Learn how this stealth technology changes the global security balance.

Ukraine’s SBU domestic security service has released new footage it says shows the country’s preparations for attacking a Russian submarine in the Black Sea port of Novorossiysk earlier this month.

A video of the attack on Novorossiysk with the Sub Sea Baby drone shows a calm port with several ships before a massive explosion kicks up water and debris.

As it tried to demonstrate its continuing ability to fight, Ukraine said it had used drones to inflict serious damage on a Russian Kilo-class submarine at a Black Sea port.

A British naval supply ship with an on-board helicopter was deployed to track the stealthy Kilo-class submarine Krasnodar, the Royal Navy said.

Hanwha Group claims that its Philadelphia plant could support construction of advanced submarines, such as the Virginia-class, if the U.S. government approves and formalizes the plan.

SEOUL--Hanwha’s Philly Shipyard has the capability of building ⁠a nuclear-powered submarine for ‌the U.S. Navy, said ‍Alex Wong, global chief strategy officer at Hanwha Group, according to a statement from the South Korean company on Thursday.